French astronomer Charles Messier was a keen comet hunter and often came across nebulous and comet-like objects during his observations which turned out not to be comets at all. In order to avoid confusion with comets, Messier compiled a catalogue of astronomical objects, which could be mistaken for comets, between the years 1758 and 1782.

Did you know...  Pierre Méchain, a French astronomer and assistant to Charles Messier, discovered as many as 30 of the objects in Messier's catalogue. Messier checked Méchain's observations and added them to his list.

The list started at 45 objects and was later added to. There is some doubt whether Messier really could have mistaken the highly conspicuous Pleiades (M45) for a comet and may have added it purely just to bump the list up to 45 objects.

  

Below is a table of the complete Messier Catalogue from M1 to M110.

 

*I am unsure which object Messier Object 102 refers to as in some textbooks it is referred to as a duplicate of M101 so it is debatable that the Spindle Galaxy (NGC 5866) is actually Messier object 102. But as most sources describe it as the Spindle Galaxy I have placed it on the list. It would also seem pointless to place M101 on the list twice.

 

 

 

 

 

 h2g2 - M45 The Pleiades The NGC and Other Designations

 Crab Nebula - Wikipedia